AVP2 Disc Data removed HELP PLEASE

[WoodDisc]

Today I was trying to find ways to get maps I downloaded to play and I must of done something because all the data on AVP2 has been removed. My CD drive reads it as a blank-disc. Would restoring my computer to a early point - (System restore in the help and support section) reverse what I did? or better yet as I use gamespy arcade sometimes I can play the game without the disc, but I don't think theres a way to download single/multilayer maps is there a way that I don't know about without the disc? Or does this mean I have to re-buy the game in order to install maps off the internet help would be great thank you.